Replacing low density with high density shouldn't have to touch outdoor/public spaces. I live in Denver and people from around my state complain about this all the time. Perfectly possible to keep (or even expand) recreation spaces if we allow more density. Might be better to argue about increased population use of same public recreation resources (crowded trails) but that's the same selfish complaints as this whole thread - it comes down to why some feel because they have it already that they should be able to exclude others from having it in the future.
Replacing low density with high density shouldn't have to touch outdoor/public spaces [...] Perfectly possible to keep (or even expand) recreation spaces if we allow more density.
Right, I'm pretty sure I specifically acknowledged this in my previous comment.
why some feel because they have it already that they should be able to exclude others from having it in the future
If some hypothetical resource has a determinate carrying capacity and any greater usage degrades the resource for everyone, it's not unreasonable to exclude people. See the fixed number of backcountry permits Yosemite issues. Some things simply cannot be had by everyone. Given this, how do you decide who gets, and who does not get?
We really only have three systems that I know of- 1) lottery, ala Yosemite permits 2) free market, ala Bay Area low density housing, also ski condos 3) precedent/i-was-there-first, ala people who already own a house there get to stay there as it becomes desirable, also prescriptive easements of public trails on private land